Looks like I'm wrong. The "Steering" info wasn't from CNN. It's from this Huffington Post article: http://www.huffingtonpost.com/2014/03/16/malaysia-airlines-takeover_n_497288.... I still would like to know how the satellite knows.
It also says that these "pings" occur every hour, so I suppose it could have kept flying for an hour after the last contact. Tom WB8WOR
On Mon, Mar 17, 2014 at 11:28 AM, Tom Busch tom@bloomington.com wrote:
The news has been reporting that they are using the angle of the last known ping from the ACARS system to the satellite. This is where the 40-degree arc around the satellite comes from.
What I don't understand is how INMARSAT knows what that angle is. CNN says that the satellite steers its antenna to the location where it expects the next ping, but that doesn't make sense.
I have been looking for the algorithm, but I can't find it. Signal strength? Some sort of electronic steering? Trade secret? I don't know.
Tom WB8WOR
On Sun, Mar 16, 2014 at 10:57 PM, R.T.Liddy k8bl@ameritech.net wrote:
Tony,
They would use the time differential between receipt to measure the distance versus the location of the satellites. The more satellites, then the more accurate the triangulation.
73, Bob K8BL
From: Anthony Japha tjjapha@earthlink.net To: amsat-bb amsat-bb@amsat.org Sent: Sunday, March 16, 2014 4:49 PM Subject: [amsat-bb] Malaysian airliner puzzle
Thanks Rick, How do those sats determine distance to the source? Tony, N2UN
This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb